Corrosion under insulation (CUI) is a condition in which an insulated structure such as a metal pipe suffers corrosion on the metal surface beneath the insulation. As the corrosion cannot be easily observed due to the insulation covering, which typically surrounds the entire structure, CUI is challenging to detect. The typical causes of CUI are moisture buildup that infiltrates into the insulation material. Water can accumulate in the annular space between the insulation and the metal surface, causing surface corrosion. Sources of water that can induce corrosion include rain, water leaks, and condensation, cooling water tower drift, deluge systems and steam tracing leaks. While corrosion usually begins locally, it can progress at high rates if there are repetitive thermal cycles or contaminants in the water medium such as chloride or acid.
When CUI is undetected, the results of can lead to the shutdown of a process unit or an entire facility and can lead to catastrophic incidents. Since it is a hidden corrosion mechanism, the damage remains unnoticed until insulation is removed or advanced NDT (non-destructive testing) techniques, such as infrared thermography, are used to ascertain the metal condition beneath the insulation. Removal of insulation can be a time-consuming and costly process, while the accuracy of NDT techniques can be insufficient due to the large number of variables (e.g., geometrical, environmental, material-related), that cause false positives (incorrect detection of corrosion) and false negatives (incorrect non-detection of corrosion) in the detection process. Additionally, many facilities have elevated networks of pipes that are difficult to access, requiring scaffolding for visual inspection.
Due to these challenges, it has been found that localized visual inspections of assets are not reliably effective at detecting CUI, and they do not reflect conditions of the assets. There is a related technical gap in predictive risk assessment of CUI. Accordingly, there is a pressing need for improved detection and risk assessment tools to determine levels of CUI damage, institute proper maintenance scheduling, and reduce the burdensome costs imposed by this problem.
It is with respect to these and other considerations that the disclosure made herein is presented.